Creates a 'range' Array, extracted from Liquid.js

range.js

// Creates a 'range' Array, extracted from Liquid.js
function makeRange(from, to) {
  var arr= [],
      left= parseInt(from),
      right= parseInt(to);
  // Check if left and right are NaN, if so try as characters
  if( isNaN(left + right) ) {
    // TODO Add in error checking to make sure ranges are single 
    // character, A-Z or a-z, etc.
    left = from.charCodeAt(0);
    right = to.charCodeAt(0);

    var limit = right-left+1;
    for (var i=0; i<limit; i++) arr.push(String.fromCharCode(i+left)); 
  } 
  else { // okay to make array
    var limit = right-left+1;
    for (var i=0; i<limit; i++) arr.push(i+left); 
  }
  return arr;  
}